Alicyclic amido-quaternary ammonium anti-bacterial agents

ABSTRACT

Novel quaternary ammonium compounds containing two large aliphatic or alicyclic groups, one of which is separated from the quaternary nitrogen by an amide linkage.

The present application is a continuation-in-part of copendingapplication serial No. 400,097, filed Sept. 24, 1973, now U.S. Pat. No.3,928,411, granted Dec. 23, 1975, which is a continuation of U.S. Pat.application Ser. No. 39,536 filed May 21, 1970, now abandoned.

The present invention relates to novel quaternary ammonium compoundsrepresented by the general formula: ##STR1## wherein R is an aliphaticor alicyclic group containing 7-13 carbon atoms, R² and R³ are eachmethyl or ethyl, R⁴ is an aliphatic chain containing 10-18 carbon atoms,n is the integer 2 or 3 and X is a compatible anion such as the halides(Cl⁻,Br⁻,I⁻), sulfates (i.e., methyl sulfate), nitrates, arylsulfonates, etc. These quaternary compounds possess superiorantimicrobial, anticaries, and anticalculus activity.

The alicyclic group may be any ring system such as the adamantyl radicalwhich is derived from tricyclo-[3.3.1.1³,7 ]decane showing four fusedchair cyclohexane rings as follows: ##STR2## a bicyclo [3.3.0] octaneshowing two joined pentane rings as follows: the norbornane radicalwhich is represented by the following ring structure: ##STR3## or anyother aliphatic ring system containing 7 to 13 carbon atoms.

Typical examples of the quaternary ammonium compounds which may be usedin this invention are:

1. 3-Heptaneamidopropyldimethyltetradecyl ammonium chloride,

2. 3-Decaneamidopropyldimethyltetradecyl ammonium chloride,

3. 3-Octaneamidopropyldimethyldecyl ammonium iodide,

4. 3-Octaneamidopropyldimethyldodecyl ammonium iodide,

5. 3-Octaneamidopropyldimethyltetradecyl ammonium chloride,

6. 3-Nonaneamidopropyldimethyltetradecyl ammonium chloride,

7. 3-Dodecaneamidopropyldimethyltetradecyl ammonium chloride,

8. 3-Undecaneamidopropyldimethyltetradecyl ammonium chloride,

9. 3-(1'-adamantanecarboxamido)propyldimethyldodecyl ammonium bromide,

10. 3-(1'-adamantanecarboxamido)propyldimethyltetradecyl ammoniumbromide,

11. 3-(1'-adamantanecarboxamido)propyldimethyltetradecyl ammoniumchloride,

12. 2-(1'-adamantanecarboxamido)ethyldiethyldecyl ammonium bromide,

13. 2-(1'-adamantanecarboxamido)ethyldiethyldodecyl ammonium bromide.

14. 3-(exo,cis-Bicyclooctane-2-carboxamido)propyltetradecyl dimethylammonium bromide,

15. 3-(exo,cis-Bicyclooctane-2-carboxamido)propyldodecyldimethylammonium bromide,

16. 3-(2'-norbornanecarboxamido)propyltetradecyldimethyl ammoniumbromide.

Other halides and analogous compounds such as the sulfates, nitrates,aryl sulfonates, etc. may also be employed herein as effectivebactericides.

It has been observed that the compounds generally described by theforegoing formula are particularly effective against gram positiveorganisms such as Staphylococcus aureus; Streptococcus mitis, sanguisand mutans; Bacillus subtilis; Corynbacterium acnes; Actinomycetesnaeslundii; and against fungi, such as Candida albicans, Trichophytonmentogrophytes and Aspergillus niger; and moderately effective againstEscherichia coli which is a gram negative bacteria. Compounds wherein R⁴is a benzyl radical in lieu of instant higher alkyl radical are devoidof antibacterial activity.

The anti-microbial nature of the instant novel compounds was shown by astandard test tube serial dilution test in which an appropriate numberof test tubes of broth containing decreasing concentrations of the testagent was innoculated with the test organism. After a suitable period ofincubation, the tubes were examined for the presence or absence ofgrowth. The activity of the test agent was the lowest concentrationwhich inhibited the growth of the organism and is expressed as theminimal inhibitory concentration in ppm. As shown in the following tableof antimicrobial data, a definite break occurs between compounds whereinR⁴ contains 8 carbons and 10 carbons.

                                      TABLE I                                     __________________________________________________________________________    Minimum Inhibitory Concentration (ppm)                                         ##STR4##                                                                               R.sup.4 = C.sub.4 H.sub.9                                                            C.sub.6 H.sub.13                                                                   C.sub.8 H.sub.17                                                                   C.sub.10 H.sub.21                                                                  C.sub.12 H.sub.25                             __________________________________________________________________________    S. aureus 100    100  25   3.12 1.56                                          Str. sanguis                                                                            50     50   50   6.25 3.12                                          Str. mutans                                                                             100    100  25   6.25 0.78                                          A. naeslundii                                                                           100    50   12.5 1.56 0.39                                          C. albicans                                                                             100    100  50   6.25 1.56                                          T. mentagrophytes                                                                       50     50   50   50   3.12                                          A. niger  100    100  100  50   12.5                                          __________________________________________________________________________

These dilution tests evidence the effectiveness of compounds of theinvention against bacteria and fungi not possessed by amidoquaternaryammonium compounds containing 3 lower aliphatic radicals.

When used against bacteria or fungi, compounds of the instant inventionmay be applied directly to the surface to be protected or may bedissolved in a pharmaceutical carrier. Typically, an effective amount,e.g., 0.025 to about 10% by weight of the compound, is included in aninert carrier and a dispersing or surface-active agent. Alternatively,an effective amount, e.g. 0.025 to about 10% by weight may beincorporated into a solid carrier which may be inert, such as talc,clay, diatomaceous earth, flour, etc.

The quaternary ammonium amides of adamantanecarboxylic acid areparticularly effective in inhibiting the development of dental calculusas shown by the results of tests on littermated albino rats, in groupsof 15 males and 15 females who were fed a Zipkin-McClure calculusproducing diet. For six weeks the teeth of each animal were swabbed forthirty seconds each day with a test solution or water for the controlgroup. The animals were then sacrificed, defleshed and scored by Baer'smethod for calculus. The results were analyzed by Student's t test andin the results quoted were 99% significant.

    ______________________________________                                                  Concentration                                                                            Calculus Reduction %                                     ______________________________________                                        Compound    Test Solution                                                                              Males      Females                                   ______________________________________                                        3-(1'-adamantane-                                                                         .1%          43.43      6.27                                      carboxamido)                                                                  propyl tetradecyl                                                             dimethyl ammonium                                                             bromide                                                                       ______________________________________                                    

The results set forth above indicate the significant effectiveness ofthe quaternary compounds of the invention in inhibiting formation oforal calculus in concentrations as low as 0.1%.

When compounds of the instant invention are intended for use incompositions which reduce formation of caries and inhibit formation oforal calculus, they are typically incorporated in oral preparation ineffective amounts up to about 5% by weight, preferably 0.025-1% and mostpreferably 0.25-0.5% by weight of the oral preparation. Typically, theoral preparation is a dentifrice, such as a dental cream, tablet orpowder, containing as a vehicle about 20-95% by weight of awater-insoluble polishing material, preferably including water-insolublephosphate such as dicalcium phosphate, tricalcium phosphate,trimagnesium phosphate. The dentrifrice may also include water; binderssuch as glycerine, sorbitol, propylene glycol and polyethylene glycol400; detergents; gelling agents such as Irish moss and sodium carboxymethyl cellulose; additional antibacterial agents; coloring or whiteningagents; preservatives; silicones; chlorophyll compounds; additionalammoniated materials; flavoring or sweetening materials; and compoundswhich provide fluorine-containing ion such as sodium fluoride, stannousfluoride and sodium monofluorophosphate.

The oral preparation may also be a liquid such as mouth rinse whichtypically contains 20-99% by weight of an aqueous lower aliphaticalcohol, preferably having about 1-30% by weight alcohol such asethanol, n-propyl, or isopropyl alcohol.

Such oral preparations are typically applied by brushing the teeth orrinsing the oral cavity for 30-90 seconds at least once daily. Typicaloral preparations of the invention which can be applied in this mannerare set forth below.

EXAMPLE 1 Dental Cream

    ______________________________________                                                                 %                                                    ______________________________________                                        3-Decaneamidopropyldimethyltetradecyl ammonium                                 chloride                  0.50                                               Nonionic detergent*        1.00                                               Glycerine                  22.00                                              Sodium pyrophosphate       0.25                                               Carboxymethyl cellulose    0.85                                               Sodium saccharin           0.20                                               Sodium benzoate            0.50                                               Calcium carbonate (precipitated)                                                                         5.00                                               Dicalcium phosphate dihydrate                                                                            46.75                                              Flavor                     0.80                                               Water                      22.15                                              ______________________________________                                         *Tween 80-Polyoxyethylene (20 moles ethylene oxide) sorbitan monooleate. 

EXAMPLE 2 Mouthwash

    ______________________________________                                                                 %                                                    ______________________________________                                        Quaternary ammonium amide of adamantane                                       carboxylic acid            0.025                                              Nonionic detergent (Pluronic F-68)*                                                                      1.00                                               Ethyl alcohol (containing flavor)                                                                        15.00                                              Glycerine                  10.00                                              Saccharin                  0.02                                               Water                      73.73                                              ______________________________________                                         *Block polymer of 80% polyoxyethylene and 20% polyoxypropylene.          

The quaternary ammonium amides of instant invention can be prepared by atwo-step method of reacting a carboxylic acid, ester or acid chloridewith N,N-dialkylethylene diamine or N,N-dialkylpropylene diamine to forma tertiary amino amide and subsequently quaternizing with an alkylhalide or ester of sulfuric or of arenesulfonic acid (i.e., methylp-toluenesulfonate) as illustrated by the following equations wherein R,R², R³, R⁴ have the aforedefined meanings. ##STR5##

The following examples illustrate the manner in which compounds of thisinvention are prepared.

EXAMPLE 3

Preparation of3-(1'-adamantanecarboxamido)propyldodecyl-dimethylammonium bromide: 2.5grams of N,N-dimethyl-1,3-propane diamine was added to a cold solutionof 5 grams 1-adamantane carboxylic acid chloride in 15 cc benzene. Animmediate precipitate formed. The mixture was stirred and permitted tosit for thirty minutes. The precipitate was washed with benzene severaltimes, centrifuged, and dried in vacuum, yielding 5 grams ofN-(3-dimethylaminopropyl)adamantane-1-carboxamide hydrochloride having amelting point of 154°-157° C. This product was dissolved in 150 ccacetone, placed in a refrigerator for crystal growth and 4.8 gms of theproduct was recovered.

This hydrochloride was dissolved in 100 cc water and 25 cc of 1N NaOHwas added. A white precipitate formed which was extracted with ether,dried by flash evaporation and 3.2 grams of the free base having amelting point of 78°-80° C. was recovered. The infrared spectrumconfirmed the structure of this product.

The aforedefined reaction product was quaternized by reacting 1.6 grams(.06 mole) of N-(3-dimethylaminopropyl)-1-adamantanecarboxamide with 1.5grams (.06 mole) of 1-bromododecane dissolved in 4 cc acetone. Afterstanding for two weeks, the reaction mixture was chilled with dry ice.The resultant crystalline mass was washed with ether, dried in vacuum,and recrystallized from ethyl acetate, giving a crystalline producthaving a melting point of 122°-124° C. and the following analysis:

    ______________________________________                                                         Found     Calculated                                         ______________________________________                                        Carbon             64.81       65.47                                          Hydrogen           10.84       10.40                                          Molecular weight: 513.66                                                      ______________________________________                                          EXAMPLE 4

The tetradecyl homolog of the above carboxyamide was prepared inaccordance with the process of Example 3. The recovered crystals had amelting point of 120°-122° C. and the following analysis:

    ______________________________________                                                         Found     Calculated                                         ______________________________________                                        Carbon             65.80       66.52                                          Hydrogen           10.54       10.61                                          Molecular weight: 541.71                                                      ______________________________________                                    

EXAMPLE 5

Preparation of 3-Decanamidopropyldimethyltetradecylammonium chloride: Asolution of 102 g (1 mol) N,N-dimethylpropylene diamine in 400 mlbenzene was stirred during the addition of 95.3 g (0.5 mol) decanoylchloride and kept below 50° C. with an ice bath. After standingovernight at room temperature, the reaction mixture was poured into 1liter of 2% sodium hydroxide solution. The benzene layer was separatedand combined with four subsequent 100 ml ether extracts of the aqueouslayer. The organic solution was washed with water and dried over sodiumsulfate. Vacuum evaporation left 116.5 g oil (91% yield). Infrared andnmr spectra showed the product to be N-(3-dimethylaminopropyl)decamide.

26 g (0.1 mole) of the above amino amide was mixed with 23 g (0.1 mole)1-chlorotetradecane and maintained in an oven at 100° C. for 70 hours.The reaction mixture was cooled to room temperature, washed with etherand recrystallized successively from acetone and ethyl acetate, giving acrystalline monohydrate product having a melting point of 55°-57° C. toliquid crystal, and 173° C. to liquid. Upon drying said monohydrate at75° C., a hygroscopic anhydrous form is obtained. This product,calculated for C₂₉ H₆₁ ClN₂ O.H₂ O has the following analysis:

    ______________________________________                                                       Found       Calculated                                         ______________________________________                                        Carbon           69.09         68.66                                          Hydrogen         12.66         12.52                                          Nitrogen         5.59          5.52                                           Chlorine         6.98          6.99                                           ______________________________________                                    

EXAMPLE 63-(exo,cis-Bicyclo[3.3.0]octane-2-carboxamido)propyltetradecyldimethylammoniumbromide

To a solution of 23 g exo,cis-bicyclo[3.3.0]octane-2-carboxylic acid(Organic Syntheses 47 10) in 100 ml benzene was added 12 ml thionylchloride and 1 ml dimethyl formamide. The reaction mixture was stirred15 minutes at room temperature and then dry nitrogen gas was bubbledthrough the solution for 30 minutes to remove HCl. The solution of acidchloride was transferred to a dropping funnel and slowly added to astirred solution of 34 g N,N-dimethylpropylenediamine in 100 ml benzeneat 20°-25° C.

After 30 minutes, the reaction was worked up by pouring into sodiumhydroxide solution and extracting the product with ether. Hydrochloricacid solution was added for neutralization and again extracted withether. Evaporation of the ether left 31 g of a crystalline solid (86% oftheory). Recrystallized from hexane, it melted at 60°-63° C.

Analysis - Neutral equivalent: Calcd, 238.4 Found, 241.3

A mixture of 12 g of the above compound and 14 g 1-bromotetradecane in100 ml acetone was refluxed for 24 hours. On chilling, 20.4 g (78% oftheory) crystals separated. After crystallizing from acetone, thecompound melted at 119°-122° C.

Analysis: Based on C₂₈ H₅₅ BrN₂ O:

    ______________________________________                                                       Calculated   Found                                             ______________________________________                                        Carbon           65.21          65.05                                         Hydrogen         10.75          10.81                                         Bromine          15.50          15.26                                         Nitrogen         5.43           5.21                                          ______________________________________                                    

EXAMPLE 73-(exo,cis-Bicyclo[3.3.0]octane-2-carboxamido)propyldodecyldimethylammoniumbromide

Prepared by the same procedure as in Example 6, this compound melted at119°-120.5° C.

Analysis: Based on C₂₆ H₅₁ BrN₂ O:

    ______________________________________                                                       Calculated   Found                                             ______________________________________                                        Carbon           64.04          64.01                                         Hydrogen         10.54          10.64                                         Bromine          16.39          16.21                                         Nitrogen         5.75           5.57                                          ______________________________________                                    

EXAMPLE 8 3-(2'-Norbornanecarboxamido)propyltetradecyldimethylammoniumbromide

Prepared by a similar procedure as in Example 6 starting with2-norbornanecarboxylic acid chloride. Recrystallized from ethyl acetate,the compound melted at 129°-131° C.

Analysis: Bromide: Calc. 15.93%. Found, 15.61%.

The superior and unexpected antimicrobial activity exhibited by thenovel compounds of instant invention is clearly shown by theantimicrobial results in Tables II and III.

                                      TABLE II                                    __________________________________________________________________________    Minimum Inhibitory Concentration (ppm)                                                       Comp.14                                                                             Comp.15                                                                             Comp.16                                                                             Comp.9                                                                             Comp.10                                 Microbe   Comp.3                                                                             (Ex.6)                                                                              (Ex.7)                                                                              (Ex.8)                                                                              (Ex.3)                                                                             (Ex.4)                                  __________________________________________________________________________    S. aureus 12.5 0.78  1.56  1.56  0.78 0.39                                    Str. sanguis                                                                            6.25 6.25  3.12  1.56  --   --                                      Str. mitis                                                                              --   --    --    --    0.39 0.39                                    Str. mutans                                                                             0.78 <0.05 0.1   0.1   --   --                                      A. naeslundii                                                                           12.5 <0.05 0.19  0.1   --   --                                      E. coli   50.  50    25    50    50.0 25.0                                    P. aeruginosa                                                                           25   50    25    50    --   --                                      C. albicans                                                                             6.25 3.12  3.12  3.12  6.25 6.25                                    T. mentagrophytes                                                                       12.5 3.12  6.25  6.25  12.5 25.0                                    A. niger  25   25    25    25    25.0 50.0                                    __________________________________________________________________________

                                      TABLE III                                   __________________________________________________________________________    [R CONH(CH.sub.2).sub.3 N(CH.sub.3).sub.2 R.sup.4 ] X                                                             J.menta-                                  R       R.sup.4                                                                            X  S.aureus                                                                           S.mitis                                                                            E.coli                                                                            C.albicans                                                                          grophyte                                    C.sub.11                                                                            C.sub.1                                                                            I  50   50   50  50    50                                          *C.sub.7                                                                            (branch)                                                                      C.sub.12                                                                           I  1.56 3.12 50  3.12  12.5                                        *(C.sub.4 H.sub.9)                                                                  (C.sub.2 H.sub.5)                                                                  CH                                                                 C.sub.8                                                                             C.sub.12                                                                           I  0.78 1.56 12.5                                                                              1.56  12.5                                        *C.sub.7                                                                            (branch)                                                                      C.sub.14                                                                           Cl .78  1.56 50  3.12  6.25                                        C.sub.7                                                                             C.sub.14                                                                           Cl .78  1.56 50  3.12  3.12                                        C.sub.8                                                                             C.sub.14                                                                           Cl 1.56 0.78 100 1.56  3.12                                        C.sub.9                                                                             C.sub.14                                                                           Cl 3.12 6.25 100 3.12  6.25                                        C.sub.11                                                                            C.sub.14                                                                           Cl 6.25 12.5 100 25    25                                        __________________________________________________________________________

The above table clearly shows that the novel amidoquaternary ammoniumcompounds of instant invention which contain two large aliphatic oralicyclic groups possess unexpectedly superior antimicrobial propertiesnot present in prior art quaternary ammonium compounds (compound 1 inTable III, and first 3 compounds in Table I).

Although this invention has been described with reference to specificexamples, it will be apparent to one skilled in the art that variousmodifications may be made thereto which fall within its scope.

I claim:
 1. A chemical compound having the structural formula: ##STR6##wherein R is an alicyclic group seclected from the group consisting ofan adamantyl group, a bicyclooctane group and a norbornane group, R² andR³ are independently a methyl or ethyl group, R⁴ is an alkyl chainconsisting of 10-18 carbon atoms, n is the integer 2 or 3 and X is ananion selected from the group consisting of halides, sulfates, nitratesand arylsulfonates.
 2. A chemical compound as set forth in claim 1,wherein R is an adamantyl group.
 3. A chemical compound as set forth inclaim 1, wherein R is bicyclooctane.
 4. A chemical compound as set forthin claim 1, wherein R is norbornane.
 5. A chemical compound as set forthin claim 1, wherein X is a halide. 6.3-(1'-adamantanecarboxamido)propyltetradecyldimethylammonium bromide. 7.A composition comprising an effective antimicrobial amount of thecompound of claim 1 admixed with a pharmaceutical carrier.
 8. Acomposition comprising an effective antimicrobial amount of the compoundof claim 1 admixed with an oral preparation.